Renewable Energy & Advanced Power Electronics Research Lab
Minjeong Kim presented her research during the Texas A&M Energy and Power Research Day, College Station, TX, USA
Ph.D. student Ms. Minjeong Kim gave a presentation entitled “Control of capacitorless ac link inverters ” at the Texas A&M Energy and Power Group Research Day in College Station, Tx, USA on November 8, 2019.
In the presentation, Minjeong discussed the advantages of an ac-link inverter over the traditional dc-link topology and presented new control methods that she developed to ensure safe and proper commutation. The dc-link capacitor is well-known to be an Achilles heel, causing reliability problems and reducing the lifetime of inverters. The ac-link inverter eliminates the rectification step in a conventional two-stage inverter and processes the square-wave link voltage directly into grid-compatible sinusoidal voltage. Ms. Kim discussed new control methods for the three-phase voltage sourced high-frequency ac link inverters and presented results from her research.
Dr. Wesam Rohouma presented a paper co-authored with Dr. Robert Balog, Ph.D. student Mr. Aaqib Ahmad Peerzada, and Dr. Miroslav M. Begovic entitled “Use of D-STATCOM for Solid State LED Lamp Harmonic Power Mitigation” at the GCC Power 2019 Conference & Exhibition in Muscat, Oman on 29th October 2019.
In this paper, a matrix converter topology-based distribution static synchronous compensator (D-STATCOM) is proposed for use in the low voltage distribution network to compensate the harmonics generated from the LED lamps. The D-STATCOM is controlled using a finite control set model predictive control (FCS-MPC). This capacitor-less topology is well-suited for long-life applications under hot environmental conditions. Experimental studies were performed, and the results obtained showed the effectiveness of the proposed technology in harmonics power mitigation.
Dr. Wesam Rohouma presented a paper co-authored with Dr. Robert Balog, Ph.D. student Mr. Aaqib Ahmad Peerzada, and Dr. Miroslav M. Begovic entitled “Capacitor-less D-STATCOM for Voltage Profile Improvement in Distribution Network with High PV Penetration” at the GCC Power 2019 Conference & Exhibition in Muscat, Oman on October 28, 2019.
In this paper, Distribution static synchronous compensator (D-STATCOM) based matrix converter (MC) is proposed for use in a low voltage distribution network to provide the necessary voltage support. This technology is reliable and has long service life as it employs inductive energy storage instead of the capacitive elements which will improve the system reliability, controlled by finite-set model predictive control. Experimental results are provided to show the effectiveness of the proposed technology.
Dr. Wesam Rohouma presented a paper co-authored with Dr. Robert Balog, Ph.D. student Mr. Aaqib Ahmad Peerzada, and Dr. Miroslav M. Begovic entitled “Impact of High Capacity Distributed Photovoltaic Systems on the Mechanical Assets in Distribution Systems” at the GCC Power 2019 Conference & Exhibition in Muscat, Oman on October 28, 2019.
The paper studies the impact of the high photovoltaic penetration on the electromechanical devices present on a distribution feeder for voltage regulation. The results of the paper indicate that the tap operations of voltage regulators follow an increasing trend with the PV penetration and saturate at about 90% PV penetration on the feeder. The simulation is based on the standard IEEE 34 node feeder model, which is modified to include a high penetration of PV power.
Ph.D. student Morcos Metry presented his paper titled “Sensorless current MPPT technique for PV energy harvesting systems in the GCC” at the Gulf Corporation Countries International Council on Large Electric Systems (GCC-CIGRE) on October 28, 2019
The paper presents an MPC based framework for sensorless current maximum power point tracking (MPPT). This paper illustrates how the sensorless current MPPT reduces the hardware cost of the dc optimizer and alleviates the issues of temperature and aging drift associated with the current sensor. Such work is of particular significance to the GCC region, where soaring desert heat poses special challenges to the PV power processors. The results of this paper are analyzed in light of irradiance and temperature data collected from the city of Doha. Data for the study was provided by the Qatar Environment and Energy Research Institute (QEERI) from the outdoor test facility.
Dr. Balog attends Industry Advisory Board meeting for NSF I/UCRC and gives an update on the Texas A&M Site, Fort Collins, Colorado USA
The Renewable Energy and Advanced Power Electronics Lab were pleased to hosted members of the Joint Advisory Board of the Texas A&M University at Qatar for a lab tour. Research Scientist Dr. Wesam Rohouma, Research Assistant Ms. Sawsan Shukri, and Ph.D. student Morcos Metry presented their research projects. Undergraduate students Mr. Seif Elgazar, Mr. Abdelrahman Amer, and Ms. Nabila Elbeheiry presented their senior design project.
REAPER Lab congratulates Mr. Moustafa Raslan for successfully defending his MS thesis, “Shape Memory Alloy Actuated Switch (SMAAS).” Mr. Raslan’s research studied the feasibility of using shape memory alloy as a mechanism for actuating an electrical switch. He evaluated several candidate designs, downselecting to feasible designs which were then prototypes to demonstrate the functionality. Mr. Raslan’s contributions are expected to enable an entirely new type of electrical switch, capable of being miniaturized using micro-electro-mechanical (MEMs) techniques. His research resulted in a US patent application in addition to scholarly publications.
Mr. Raslan received his B.Sc. with honors in Mechanical Engineering from Texas A&M University in Qatar in May 2017. He is currently pursuing an M.Sc. in Interdisciplinary Engineering in the REAPER lab at Texas A&M University with a focus area spanning Mechanical, Electrical and Materials Engineering. His research interests include electro-mechanical systems, applications of shape memory alloy materials, and microfabrication.
Minjeong Kim presented a paper at the IEEE Energy Conversion Congress and Exposition (ECCE) in Baltimore, MD USA
Ph.D. student Ms. Minjeong Kim presented her paper entitled “New commutation method based on state machine for three-phase HF ac link inverter with passive loads” at the IEEE Energy Conversion Congress and Exposition in Baltimore, MD USA
The paper proposes a new commutation method based on state machine for a three phase HF ac link inverter. The new commutation method overcomes the disadvantages of the commutation method for a single phase HF ac link inverter by controlling all the switches of three phase ac-ac converter by one state machine. The THD values of the output currents are compared and the results prove that the newly proposed state machine removes the distortions.